That we think have no cost. The massive failure rate of drug trials and some famous cases of issues discovered only after wide scale deployment indicates we're not that great at knowing ahead of time.
The body is like legacy spaghetti code written by hundreds of teams of outsourced engineers. It mostly works. Just never remove any commented out lines or it may break.
While possible, there are also many bodily processes that are finely tuned through eons of evolution, and destabilizing pressure leads to disorder. Sometimes it's difficult to know which are which (or at least I don't know).
the most straightforward example off the top of my head would be that hair follicles have no conceivable reason to react to testosterone. removing DHT receptors from them would have no adverse effect whatsoever.
have you read the story of dr. adrian thompson's ai generated fpga ? the story goes that removing seemingly redundant components caused the circuit to fail because of second order effects. for that reason, i try to avoid sweeping statements like 'no effect whatsoever' when it comes to playing god
It's important to note that evolution is not a designer, it's just a string of random mutations over millions of years that mostly work. The human body is remarkably shit at a lot of thing, like not getting heart disease. Most animals don't develop heart disease but we do... oops.
We can also live just fine without an appendix. Literally the only thing the organ can do is suddenly develop a severe infection and kill you without surgery which has only become reliably available in the past 100 years or so. (Blah blah bacterial reservoir or whatever: that's of evidently very low value compared to sudden and painful death)
There's also no reason we shouldn't be immune to funnel web poison: cats make an enzyme which deactivates it, whereas primates don't.
There is also no reason our eyes can’t see in the dark because cats can and no reason to not to lay eggs because that’s more practical and way less dangerous (and probably painful) than giving birth directly. Also too bad that we haven’t multiple hearts for redundancy.
The body is like legacy spaghetti code written by hundreds of teams of outsourced engineers. It mostly works. Just never remove any commented out lines or it may break.